It is often desirable to connect communication and/or power circuits in contaminated environments such as found in sewers, in mines, in dust storms, underwater, and in diverse terrestrial and naval battlefield operations. In many cases, it is not possible to clean the connector contacts at the moment connections are made. Fiber-optic connections are especially vulnerable to contamination. If optical contacts are not clean they will not work well, or possibly not work at all. There is a category of connectors designed primarily for rugged subsea operations that permit the contacts to be cleaned in the manufacturing process, and afterward used repeatedly without subsequent cleaning. This category includes dual-chamber connectors in which plug and receptacle units each house pin and/or socket contacts within one or more closed, oil-filled chambers. When the plug unit and receptacle unit are mated, the contacts can pass from one or more chambers of the first unit into one or more chambers of the second unit wherein each contact engages its respective counterpart without ever having been exposed to the external environment in the process. The chambers are typically substantially filled with a benign mobile substance, such as grease, gel, or oil, hereinafter simply referred to as “oil” or “fluid,” and are approximately pressure-balanced to the working environment by way of one or more movable portions of the chamber walls.
Examples of dual-chamber connectors are contained in U.S. Pat. Nos. 4,682,848; 5,286,129; 5,645,438; 5,738,535; 5,838,857; 6,095,838; 6,315,461; 6,929,404; 7,004,638; 7,344,316; 7,364,448; 8,192,089; 8,944,082; 8,511,908; 8,226,303; and in EP 0,538,089. All are characterized by the feature that before, during and after mating the plug and receptacle contacts are housed within closed oil chambers. They were all designed primarily for high-pressure underwater systems, and are extremely robust, complex, and expensive. As a result, they are not well suited for general harsh environment use or environments that are at least somewhat less harsh, thereby not requiring the same robustness or complexity or justifying the expense. Such prior art connectors would not serve to quickly and reliably connect optical circuits in a muddy foxhole, in the dark, or in the rain, for instance.
All prior-art dual-chamber connectors function generally as follows. Plug and receptacle units are brought face-to-face and aligned rotationally and axially. When thus positioned, and the units are joined, one or another mechanism creates a passageway between the units, connecting the fluid volume of the plug unit with that of the receptacle unit, thus forming, at least temporarily, one continuous fluid volume. Contacts from the first unit pass through the passageway to engage the respective contacts within the second unit. In some prior art connectors of this category, as the contacts from the first unit pass through the passageway they completely occupy the passageway, thus substantially closing it when the first and second units are completely mated; in others they do not close the passageway. However, in all dual-chamber prior-art connectors during mating and demating there is a free exchange of first unit fluid with the second unit fluid at one or more stages of the process.
In general use, dual-chamber plug and receptacle units are not dedicated pairs; in its lifetime each plug might mate with many receptacles, and vice-versa, just like the plugs and sockets in a residential home. Each time a prior art dual-chamber connector is mated, its fluid, at least temporarily, is freely mixed with the fluid of its mating counterpart. Contamination of the fluid in one connector unit, such as water or silt ingression, for instance, can be undesirably spread like a social disease, thereby degrading performance throughout the local connector population.
Despite the amount of prior art technology represented by the above-listed patents, there still does not exist in the marketplace a small, highly reliable connector that can go anywhere, whose contacts do not need to be cleaned between uses, can be connected and disconnected quickly in most any environment, does not freely exchange fluid between mating units, and yet is simple, efficient, and economical. The presently disclosed technology fulfills that and other needs in the art.